遗传多样性研究进展

目的从表型和分子标记两个角度对厚叶栒子野生种群开展研究，旨在揭示其遗传多样性。方法利用31个表型性状和30条ISSR引物对滇产野生厚叶栒子居群进行遗传多样性分析，用PopGen 32软件计算多样性指数，用SPSS 16.0软件构建系统发育树系图。结果厚叶栒子居群间表型性状差异较小；30条ISSR引物扩增出282条带，其中231条具有多态性，平均多态率为81.91%，Nei’s基因多样性指数和香农多样性指数分别为0.414 1和0.597 9。采用UPGMA法构建的形态和分子标记两种树系图基本一致，分布在同一区域的各个居群多数能聚在一起，地理位置的隔离促进了厚叶栒子居群间的遗传分化；个别居群未能与同一区域的其他居群聚在一起，其原因可能是同一区域内各居群的小生境不完全相同，而不同区域间也有相似的小生境，导致厚叶栒子居群间发生了趋同进化。结论滇产野生厚叶栒子具有丰富的遗传多样性，研究结果为厚叶栒子种质资源的开发利用提供了科学依据。

RAPD analysis of interspecific relationships in presumably apomictic Cotoneaster species

PurposeIn order to reveal the level of genetic diversity of wild populations of Cotoneaster coriaceus from phenotypic traits and molecular marker.MethodThe 31 phenotypic traits and 30 ISSR primers were used to investigate the genetic diversity of wild populations of C. coriaceus in Yunnan. The diversity indice were calculated by PopGen 32 software and the phylogenetic trees were constructed by SPSS 16.0 software.ResultsThere was a little difference in phenotypic traits among various populations. In total 282 bands were detected by 30 ISSR primers, 231 of them were polymorphic and the percentage of polymorphic bands was 81.91%. The Nei’s gene diversity index was 0.414 1 while the Shannon diversity index was 0.597 9. The 2 phylogenetic trees based on phenotypic traits and ISSR markers by UPGMA were similar. Most of populations in the same distribution areas were classified into the same groups, while a few populations did not combine with other populations in the same distribution areas. This phenomenon indicated that the geographical isolation promoted genetic differentiation and there were convergent evolution due to the similar micro-habitat.ConclusionThere was abundant genetic diversity in C. coriaceus in Yunnan. These research data provide a scientific basis for exploitation of C. coriaceus resources.